1. Field of the Invention
Generally, this invention relates to a medical procedure for enlarging the cross sectional area of a section of a fluid flow passageway. The invention also covers the system for performing said procedure.
Specifically, the most common medical procedure to which the instant invention relates is a percutaneous transluminal coronary angioplasty procedure, hereinafter referred to by its commonly accepted shorthand designations "PTCA" or "angioplasty." Angioplasty is most frequently called for when blood flow through one or more coronary arteries is severely restricted as the result of the accumulation of plaque deposits on the artery walls.
An accumulated deposit which results in the constriction or narrowing of the flow path is called a stenosis. The object of angioplasty is to enlarge or dilate the stenosis, and the procedure is normally accomplished by use of dilatation catheters.
2. Description of the Prior Art
An article entitled "A New Catheter System For Coronary Angioplasty" by Simpson et al, published in the American Journal of Cardiology (Apr. 1, 1982) describes the general angioplasty procedure in some detail. Numerous patents have issued, particularly over the past five years, describing a wide variety of catheters, methods for inserting and placing catheters and methods for performing angioplasty. Among those most relevant to the instant invention are U.S. Pat. Nos. 4,762,129 (Bonzel), 4,748,982 (Horzewski and Yock), 4,616,648 (Simpson); 4,468,224 (Enzmann and Lundquist), British Patent No. 2,180,454 and PCT applications having Publication Numbers WO 88/00844 and WO 86/06285.